For example, in a hand-held tool (which is also hereinafter referred to as a tool simply) such as a nailing machine, nails or screws are loaded into the magazine of a tool main body as fasteners, and are then ejected from the magazine. However, when an operator is not aware that the fasteners have been used up, there occurs a blank striking. In this case, for example, there is a fear that a member to be fastened such as a gypsum board can be damaged by a driver bit.
As means for solving this problem, it is expected to provide in a tool main body a blank striking preventive mechanism capable of preventing such blank striking. Also, it is expected to carry on the tool main body a blank striking preventive electronic apparatus capable of detecting the residual quantity of fasteners using an electronic part such as a sensor.
Here, conventionally, there is disclosed a detecting apparatus for detecting that a residual quantity of staples in a magazine is zero or small (for example, see the patent reference 1). Also, conventionally, there is disclosed a staple striking apparatus including a sensor for monitoring a feed of staples when the staples are consumed (for example, see the patent reference 2). Further, conventionally, a staple striking machine operation detecting apparatus which detects the movement of a staple advancing following the staple striking operation (for example, see the patent reference 3).
Patent Reference 1: JP-U-3-33077
Patent Reference 2: JP-A-57-89572
Patent Reference 3: JP-A-8-164503
However, the technologies respectively disclosed in the patent reference 1 to 3 relate to a stapling apparatus built in an electric stapler/copying machine placed on a base, and an automatic staple striking apparatus for striking staples under an automatic control.
When the above-mentioned blank striking preventive mechanism is provided on a hand-held tool, a weight of the hand-held tool is increased due to the present preventive mechanism. As a result, there is generated an inconvenience in the hand-held tool, for example, the hand-held tool is harder to use. Also, in some cases, in a state where the residual quantity of fasteners is not known, an operator can recognize for the first time an absence of the fastener after the operator conducts the blank striking. For example, when the operator works on a stepladder or the like, if the fastener runs short during the operation on the stepladder, the operation of the operator after then becomes complicated. Specifically, in order to load new fasteners, the operator must carry out troublesome operations; for example, the operator must climb down from the stepladder. Such operations cause the operator to waste time and labor.
Also, when the above-mentioned blank striking preventive electronic device is carried on the hand-held tool, although an electronic part such as a CPU or a sensor is small in size and light in weight, a power source part such as a battery is large in size and heavy in weight compared with the electronic part. Therefore, when the terminal of the battery is mounted onto a circuit substrate by soldering or the like, due to an impact of ejecting the fastener, there is a fear that the terminal portion of the battery can be broken. In other words, due to an inertia of the battery that is heavy in weight, a load is locally applied onto the terminal portion, whereby the terminal portion is easy to break.
When a piezoelectric vibratory plate for use in an acceleration sensor or a buzzer is mounted onto an electronic part formed in a thin film shape, for example, in a household appliance, there is generally used a method in which the outer peripheral edge of the piezoelectric vibratory plate is held by and between two parts.
As a method for avoiding the above-mentioned breakage of the battery terminal portion, there can also be expected a method in which, after the battery is mounted on the circuit substrate, the battery is further bonded to the circuit substrate using silicone-system resin or the like. However, in this method, the mounting process is hard to be automated, and also the bonding amount of the battery is difficult to control, because poor bonding sometimes occurs. Further, since the number of steps of mounting the battery increases, the mounting operation is complicated and also the mounting cost is increased.
Also, in the case of the thin-film-shaped electronic part, when the above-mentioned general method is used in a hand-held tool such as a hand tool, there are necessary exclusive parts (the above-mentioned two parts) which are used to hold the piezoelectric vibratory plate between them, whereby the weight of the whole of the tool is increased. Further, there can also be expected a method in which parts existing already are used to hold the vibratory plate between them. However, in this method, the piezoelectric vibratory plate cannot be always mounted in such a manner that, for example, an acceleration speed can be detected sufficiently or a buzzer can sound properly.